Self-hardening welding rod



Patented July 28, 1942 "UNITED STATES PATENT OFFICE No Drawing.Application August 6,1941, Serial No 405,626

5 Claims.

This invention relates to alloy steel rods and coatings in connectiontherewith which, when the coated metal rod center is melted either byoxyacetylene or electric arc melting an alloy is produced which is hardand tough, of extremely high tensile strength, and capable of forgingafter deposition upon a base iron metal. The metal may be deposited uponan underlying ferrous base to any desired degree of thickness and theheavier thicknesses may be obtained by depositing the metal in a numberof layers. The central rod is of a well known composition sold openly onthe market under the designation SAE 4150 steel. The flux coatingcontains compounds of a metallic nature, the metallic elements of whichcombine with the iron of the steel rod to produce a deposited alloyhaving the characteristics and properties which have been stated.

When the rods are melted by an oxy-acetylene it flame the coating ismade from ingredients in substantially the following proportions:crushed ferro chrome, 35 to 44%; crushed ferro manganese, 35 to 44%,graphite powder 14 to 18%. These provide the dry elements of thecoating. They are used with wet elements which consist of of 30% ofsodium silicate to 70% distilled water. The dry elements are mixed withthe wet elemerits thus provided in proportions of 60% of the dryelements to 40% of the wet elements.

When the rods are melt-ed by an electric arc the ingredients of thecoating are substantially as follows: crushed ferro chrome 25 to 30%;crushed ferro manganese 8 t6.1 0%; titanium 4 to 6%; fluorospar 7 to10%; marble 16 to 20%; graphite to The wet elements are the same asbefore, sodium silicate 30% and distilled water 70%. The elements aremixed in proportions of 37 /2% wet to 62/2% dry. Inboth cases the weightof the dry elements of the coat ings is one-quarter of theweight of theSAE 4150 steel rod upon which the coating is applied so that of thetotal weight of the rod 20% consists of the coating and 80% of the steelcenter rod.

The metal deposited when thus coated has combined with the iron 6 to 8%chromium and 2 to 3% manganese. The carbon that is present in the steelranges from 0.5 to 0.75% and there is present from 0.5 to 1% titanium.Silicon, phosphorus and sulphur are present in exceedingly small amountsor traces and if it was possible to remove them entirely there would benone. For example, silicon varies from 0.01 to 0.02% and both phosphorusand sulphur from 0.001 to 0.002%. Such silicon, phosphorus andsulphurare 25 sodium silicate and distilled water in proportions 45ously stated.

negligible and do not affect the deposit in any particular manner anddesirably there would be none of such elements if in practicalcommercial practice it was possible or feasible to entirely 5 removethem. The graphite which is in the coatings serves to maintain theproper amount of carbon in the deposited metal, mor graphite being usedwith electric are high temperatures than with the lower oxy-acetylenetemperatures. The

10 titanium which is used in the coating for electric arc melting wherethe temperature reached will exceed 8600 F. insures against nitrogenfrom the air combining with and forming undesired and damaging compoundswith the chromium and 15 iron. The small amount of titanium which is inthe deposited alloy in the electric arc melting serves to render thealloy more tough and resistant.

The deposits produced after melting and deposition upon a suitable steelbase range in hardness from 500 to 565 Brinell. Such deposits areexceedingly tough and have a tensile strength exceeding 185,000 poundsper square inch. They are highly resistant to abrasion even at hightemperatures. Such properties make the alloy particularly useful forapplication to manganese steel bases for rock handling and diggingequipment for example, the crushing mantles and jaws of rock crushers,steam shovel teeth and the like.

30 The actual fluxing material used in the coatings is small in amountso that any flux residue left is light and may be readily removed. Suchalloy may also be used to build upon a base ferrous .metal, a part ofthe abrasive resisting face of the metal and thereafter a still harderand tougher and more resistant alloy to abrasion, such as described inmy copending application filed herewith, applied as the final or outsidelayer.

When applied to steel bases, the joined together base andalloy depositmay be readily forged at heats ranging between 1700 and 2000 F.

. There are many applications of the deposited metal other than thosewhich have been previ- It may be used for coating the impellers andliners of centrifugal pumps; for covering large areas that are subjectedto impacts and abrasions, particularly in those cases where cost must bekept low; for rebuilding the tracks, guide and thrust rollers, grouserbars,

drive sprockets and other parts of caterpillar tractors subjected toabrasive wear; rebuilding Wobbler ends and clutches in steel mills;rebuilding cotton gin separator bars; and in general for repairing andincreasing the life of most parts of heavy equipment which are subjectedto great wear.

I claim:

1. A rod of steel havin: a coating of ferro chrome. ferro manganese andgraphite powder cemented tosether and located around the rod. the weiahtof steel approximating 80% of the completed rod and the ooatin:approximatina 20% thereof.

2. A rod of steel and a coatina thereforcomprisedofdryelementsofcrushedferrochrome 35 to 44%. crushed ferromanaanese 85 to 44%. and Iraphite powder 14.to 18%, and wet elementscomprisin: sodium silicate 30% and distilled water 70%. the wet and dryelements hein: mixedinproportionsof 40% wetand00% dry elements, theweiaht of steel tely in the ratio of four to 3.Arodofsteelhavinsacoatinsof mately one-fourth of the steel weiahtincluding go ferrochrome,ferromanganeseandgraphi whereby when saidcoated rod melted the melted deposit will have added to the 8% ofchromium and approximately 2 manaanue. 4

4. A of steel which consists principally iron with approximatelyone-half to three-quarters of 1% carbora'combined therewith'havinacoatin: comprisina ferro chrome 35 to ferromanganeseaotoddfiandmphitei18% cemented tosether. the coatin on the completed rod approximating 20%of the. therodandthesteelapprozimatelylo'k thereof. said rod beinaadapted to be melted iected to temperatures not eaceedins mately 3500'I.

andadherinltoaetherandtotherodtheweilht of the coatina comprisingapproximately 20% of the coated rod and the steel approximately 80%WILLIAM C. MCLO'IT.

g5 thereof.

